As will be described in greater detail hereinafter those portions of healthy gum tissue or gingivae that are situated directly adjacent to the teeth normally have an undulating configuration. This undulating configuration of the gingivae is referred to as the free gingival margin. The free gingival margin overlaps the crowns of the teeth. The fissures formed between the overlapping free gingival margin and the teeth are referred to as the sulcular regions. The gingival one third area of each tooth comprises one third of the facial surface of the crown thereof, including the portion of the crown underlying the sulcular region, that is located closest to the gingiva. The embrasure regions, that are located between the teeth, consist of the interdental papillae and the interproximal margins of the teeth. The cleansing of these above described facial areas of the teeth and the adjacent, associated gingivae, is normally neglected during ones daily regimen of oral hygiene. As a result of such neglect, the teeth and the gingivae suffer from a greater probability of decay and disease.
The reason for such neglect relates to the shape and configuration of conventional tooth brushes. As is well known in the prior art, conventional tooth brushes generally have level, planar brushing surfaces. Since, as described above, the gingivae directly adjacent to the teeth have an undulating configuration, the level, planar brushing surfaces of conventional tooth brushes generally do not clean the facial surfaces of the teeth that are proximately located with respect to the gingivae, as well as the associated sulcular regions thereof. Even when one takes special care to reach such surfaces with a conventional tooth brush, an irritation of the gingivae can result from the rubbing action of the bristles of the tooth brush across the gingivae. Another difficuly in cleansing such regions of the teeth arises from the decrease in the available vestibular area between the teeth and the oral cavity that is normally encountered towards the back of the oral cavity. The sulcular regions of the gingivae are also neglected simply because the flat brushing surface of a conventional tooth brush never reaches within the overlap of the sulcular regions. Lastly, the inline orientation of the handle of a conventional tooth brush with respect to its brushing surface inhibits the user from holding the brush head portion in a level orientation with respect to the gingival one third areas and the associated gingivae. This results in decreased brushing efficiency in that during brushing only a portion of the bristles are in contact with the facial surfaces of the teeth at any location in the oral cavity.
The need to cleanse such areas of the teeth and gingivae has long been known in the prior art. For instance in one tooth brush of the prior art, a brush head portion is provided having an outer set of bristles of uniform length and a central, intermediate set of bristles having a length less than that of the outer set of bristles. As a result, at least some bristles are operable for reaching the gingival one third areas the teeth. Another tooth brush of the prior art employs tufts of bristles having alternating lengths and tufts of bristles transversely angled towards one another. The longer bristles can thereby extend into the interproximal areas of the teeth and the crevices and depressions thereof. The adjacent, shorter tufts of bristles provide motility to the longer tufts of bristles during the cleansing of such areas of the teeth. Although such tooth brushes represent an advance over the conventional tooth brushes for cleansing the teeth and at least the interproximal regions thereof, they also have a built in design deficiency in that the regular and equal arrays of the bristles thereof do not equally cleanse all of the teeth. This is because teeth vary in size. For instance molars are larger than incisors and as such the gingival one third area of a molar is larger than that of an incisor. Additionally, the brush head portions and handles thereof are very similar in size and arrangement to conventional tooth brushes and as a result they retain the inherent problems thereof in cleansing the teeth that are situated towards the back of the oral cavity.
As will be discribed hereinafter the tooth brush of the present invention seeks to remedy the problems associated in cleaning the gingival one third areas of the teeth and the sulcular and embrasure regions by providing a tooth brush having an undulating brushing surface of convex and concave regions of tufts of bristles wherein the convex regions of the tufts of bristles differ from one another in size and curvature to coincide with the free gingival margin that is located adjacent to selected teeth. Additionally, the brush head portion itself can preferably contain a single row of bristles on a narrow cylindrical brush head portion to reach into the rearmost areas of the oral cavity. An angled handle portion is also provided, which in combination with an angled brushing surface, permits the brushing surface to remain level and in complete contact with the teeth during brushing.